An abstract adapter class for receiving mouse events.
The methods in this class are empty. This class exists as
convenience for creating listener objects.

Mouse events let you track when a mouse is pressed, released, clicked,
moved, dragged, when it enters a component, when it exits and
when a mouse wheel is moved.

Extend this class to create a MouseEvent
(including drag and motion events) or/and MouseWheelEvent
listener and override the methods for the events of interest. (If you implement the
MouseListener,
MouseMotionListener
interface, you have to define all of
the methods in it. This abstract class defines null methods for them
all, so you can only have to define methods for events you care about.)

Create a listener object using the extended class and then register it with
a component using the component's addMouseListeneraddMouseMotionListener, addMouseWheelListener
methods.
The relevant method in the listener object is invoked and the MouseEvent
or MouseWheelEvent is passed to it in following cases:

when a mouse button is pressed, released, or clicked (pressed and released)

mouseDragged

Invoked when a mouse button is pressed on a component and then
dragged. MOUSE_DRAGGED events will continue to be
delivered to the component where the drag originated until the
mouse button is released (regardless of whether the mouse position
is within the bounds of the component).

Due to platform-dependent Drag&Drop implementations,
MOUSE_DRAGGED events may not be delivered during a native
Drag&Drop operation.